Teaching Notes

Example Output

Users will create a graphic model of ocean sediment cores that represent a complete cycle of Earth's climate. After viewing an animation of ice shelf advance and retreat over the Ross Sea in Antarctica, users will create their own model cores based on what they have learned in the activity.

Grade Level

This activity is designed to provide background for educators and students on the role of sediment cores in revealing the climate change history of Earth. It can be used as a professional development activity or with students in grades 6-16.

Learning Goals

use the Paleontological Stratigraphic Interval Construction and Analysis Tool (PSICAT) program to create graphical models of ocean sediment cores;

communicate to others about the role of atmospheric and oceanic temperatures in climate change;

infer data based on a model;

revise prediction based on data collection;

describe the role of polar ice in climate change, and;

use data from ocean sediment cores from Antarctica to tell a story about climate change throughout Earth's history.

Rationale

This one-week activity engages users in an investigation of the role that ocean sediment cores play in revealing Earth's climate change story. In Part One, while on a virtual trip through the Southern Ocean, users learn about the four primary types of ocean sediments found around Antarctica. In Part Three, users use an interactive animation and make predictions about the sediment types that they would expect to see in ocean cores reflecting Earth's climate cycles. Throughout the activity, users model what field scientists do as they work through the scientific process: make observations, create a hypothesis, collect data, revise the hypothesis, collect more data, discuss, defend, analyze, and communicate their results.

The multinational ANtarctic geological DRILLing (ANDRILL) team of over 200 scientists, drillers, and technicians spent many months on the Ross Ice Shelf. There, they drilled through several hundred feet of ice and ocean water to reach the ocean floor. Then, core-by-core, they brought up over one thousand meters of sediment in order to decipher the story of climate change through geologic history.

The ANDRILL drill sites are show with stars and labeled "SMS" and "MIS" in the image below.

The results of their research are helping the scientific community make decisions about climate change policy. Their work is also guiding future climate change research and monitoring.

For more information about the ANDRILL project, visit the ANDRILL home page. On this site you will find background information, science information, media and education guides, downloads links to publications, movies and up-to-date news.

Background Information

The Earth's climate has changed dramatically over time. Places, such as Antarctica and Arizona, that were once suitable for large reptiles (having lush vegetation and warm temperatures) are now dry deserts. Land areas, such as Canada and the Rocky Mountains, once covered in ice, are now lakes and forests. The time over which these changes occurred is represented in geologic time scalestens of thousands to millions of years. Throughout its entire history, Earth's climate has oscillated between warm and cold phases. In the most recent 10,000 years our planet has enjoyed a relatively warm, stable climatic period. The current knowledge about climate change is derived from many sources: ice cores, sediment cores, rock cores, tree rings, and the fossil record. In this activity, users explore one of those sources, sediment cores from the ocean floor.

Today, our climate is changing with far-reaching impacts. Scientists around the world are working hard to understand the changes. Politicians, economists, farmers, land developers, and you and I, are among the stakeholders whose decisions will be based on the understanding of climate change. Examples of impacts include: crops that are now grown in specific areas may have to be relocated; locations where people are living today may become uninhabitable in the future; and animal habitats, such as the Arctic sea ice, are changing or disappearing.

The ocean floor receives a continuous supply of small particles that settle in layers called sediment deposits. These particles vary in their size, chemistry, and color. They originate in many places including the remains of living organisms, the atmosphere, and the land. Rocks that will become sediments are carried from the land to the ocean by rivers. In coastal marine systems, waves pound against the shore. Their force breaks down the sand and rocks. Other types of weathering include flooding and the mechanical action of ice formation. Atmospheric particles found in oceanic sediment may come from dust storms, plant spores, molds, or pollen. These particles are carried by the winds over the ocean where they are deposited. When living organisms die, they settle to the bottom of the ocean and become part of the sedimentary deposits. Shells, diatoms, and single-celled creatures leave a record of their presence in the ocean sediment when their bodies are preserved in the sediment layers.

The keys to climate records in ocean sediment cores are stored in these particles. For example, in order for marine plant life to occur, sunlight must be present. Therefore, when the polar ocean is covered with thick ice, the presence of plant life in the sediment is reduced. In times of warm temperatures and rain, there is increased erosion of rock, which triggers the addition of more land-based particles to the mix. As Earth (and its oceans) warms and cools, biological diversity and water density change in response to the warming and cooling. Populations and species may increase in number and diversity, decrease, or become extinct. These records are preserved in ocean sediments. Ash, from volcanic eruptions, settles to the ocean floor in layers. The ash record from known eruptions provides another clue that is important in the dating of the age of the sedimentary layers. If preserved intact, ocean sediment layers provide a record of changes in Earth's climate.

Listed below are some of the key questions users will respond to in this activity:

What clues in the sediment cores let researchers know how old the layers are?

Instructors may want to download and share the following PowerPoint of supplemental slides to use as background illustrations. The PPT file contains further details about the ANDRILL cores and their relationship to Antarctica's ice sheets and shelves. Slides courtesy of Dr. Ross Powell. ANDRILL Cores Supplemental Slides(PowerPoint 23.4MB Apr24 11)

Additional Resources

The links below can be used to access more information about ocean sediment coring, Antarctica, ANDRILL, and climate change. These readings may be used as homework assignments, or serve as in-depth references.

Key Terms and Prerequisite Knowledge

Beginning knowledge of ocean sedimentation and the fossil record are important prerequisite skills for users of this chapter. In addition, familiarity with tree rings, and the climate information they contain, will help students with the concept of cores and sequential layers.

The sediment core cards contain the background information and key terms needed for this activity. They are pictured in Part 1, "show me the cards". You can download these cards in PDF or PPT format from the links below.

Instructional Strategies

Set the stage for the activity by describing the ANDRILL research team. Depending on class time and facilities, teachers may want to show one of the short videos from the ANDRILL site, or the NOVA video. In the introductory exercise, the ANDRILL team is headed to the Southern Ocean and the Ross Ice Shelf in Antarctica to recover sediment cores from thousands of meters below the ocean floor. The cores will reveal clues of Earth's climate change history.

This chapter can easily be placed in a unit on Climate Change, Geology, Earth System Science, Oceanography, or Environmental Science. It applies inquiry strategies as well as teamwork, science journal writing, communication skills, and practice in the scientific method.

Listed below are some questions to get students started thinking about climate and climate change.

Climate change will alter how and where our crops are grown, areas on Earth that we want to live, transportation channels, population centers, ranges of disease-carrying insects and other pathogens, wildlife and vegetation patterns as well as weather patterns influencing water distribution around the world. Every human on Earth is a stakeholder in these changes and will need to learn how to cope.

The fossil record, ocean sediment cores, ice cores, and tree rings indicate the climate has changed both locally and globally over Earth's surface. Where ice sheets once covered the land, forests and lakes are now the dominant feature. In some places deserts exist where oceans once persisted.

Oceans interact with the atmosphere exchanging heat, gases, and dissolved particles that are discharged from the land in runoff. As Earth's climate changes, atmospheric temperature increases and decreases, changing the temperature of the oceans as well as the amount of gases that will dissolve in the ocean. This process of atmospheric exchange, along with the dissolved minerals from runoff, alters the chemistry of ocean water. These changes are reflected in the kind and number of organisms that thrive in the ocean, and their remains in sediment cores reveal the story of these changes.

Learning Contexts

The activities engage students in climate change research and will support content standards in Earth Science and Environmental Science courses. This unit provides students with an opportunity to explore an actual tool used in climate change research. The PSICAT program helps researchers record, catalog, analyze, and disseminate information about the sediment cores they retrieve from the ocean floor. It can be downloaded for free and includes a tutorial to help users get started.

8ASI2.7 Scientific investigations sometimes result in new ideas and phenomena for study, generate new methods or procedures for an investigation, or develop new technologies to improve the collection of data.

Grade 8 Science Standards

8CLS3.1 All organisms must be able to obtain and use resources, grow, reproduce, and maintain stable internal conditions while living in a constantly changing external environment.

8CLS4.1 A population consists of all individuals of a species that occur together at a given place and time.

8CLS4.4 The number of organisms an ecosystem can support depends on the resources available and abiotic factors, such as quantity of light and water, range of temperatures, and soil composition.

8DESS1.6 Water, which covers the majority of Earth's surface, circulates through the crust, oceans, and atmosphere in what is known as the "water cycle."

8DESS1.10 Global patterns of atmospheric movement influence local weather. Oceans have a major effect on climate, because water in the oceans holds a large amount of heat.

8DESS2.1 Earth processes we see today, including erosion, movement of lithospheric plates, and changes in atmospheric composition, are similar to those that occurred in the past.

8DESS2.2 Fossils provide important evidence of how life and environmental conditions have changed.

8EST1.3 Implement a proposed solution.

8EST2.1 Scientific inquiry and technological design have similarities and differences. Scientists propose explanations for questions about the natural world, and engineers propose solutions relating to human problems, needs and aspirations.

8GHNS1.2 Science requires different abilities, depending on such factors as the field of study and type of inquiry.

8GHNS2.1 Scientists formulate and test their explanations of nature using observation, experiments, and theoretical and mathematical models.

8GHNS2.2 In areas where active research is being pursued and in which there is not a great deal of experimental or observational evidence and understanding, it is normal for scientists to differ with one another about the interpretation of the evidence or theory being considered.

8GHNS2.3 It is part of scientific inquiry to evaluate the results of scientific investigations, experiments, observations, theoretical models, and the explanations proposed by other scientists.

12ASI2.1 Scientists usually inquire about how physical, living, or designed systems function.

12ASI2.2 Scientists conduct investigations for a wide variety of reasons.

12ASI2.3 Scientists rely on technology to enhance the gathering and manipulation of data.

12ASI2.5 Scientific explanation must adhere to criteria such as: a proposed explanation must be logically consistent; it must abide by the rules of evidence; it must be open to questions and possible modification; and it must be based on historical and current scientific knowledge.

12ASI2.6 Results of scientific inquiry — new knowledge and methods — emerge from different types of investigations and public communication among scientists.

Grade 12 Understandings about Science and Technology

12EST2.1 Scientists in different disciplines ask different questions, use different methods of investigation, and accept different types of evidence to support their explanations.

12EST2.2 Science often advances with the introduction of new technologies.

12EST2.3 Creativity, imagination, and a good knowledge base are all required in the work of science and engineering.

12EST2.4 Science and technology are pursued for different purposes.

12FSPSP5.1 Normal adjustments of Earth may be hazardous for humans.

12FSPSP6.2 Understanding basic concepts and principles of science and technology should precede active debate about the economics, policies, politics, and ethics of various science - and technology - related challenges.

12GHNS3.3 Occasionally, there are advances in science and technology that have important and long lasting effects on science and society.